Json Logging apply change file rotation configuration

General
1

Hello,

I changed the configuration of json logging in “/etc/docker/daemon.json” from “max-size”: “10m” to “2m”.

/etc/docker/daemon.json

{
  “data-root": ‘/var/docker/docker’,
  “log-driver": ‘json-file’,
  “log-opts": {
    “max-size": ‘2m’,
    “max-file": 
“3”
  }
}

but now the log files have a size of 10mb. (before there was only one big log file in each container folder)
Maybe the containers were created before the daemon.json.

After the change to 2m the Debian Docker host was restarted and the containers were recreated with Portainer.

Unfortunately I don’t understand why the file size for the log files is not taken over.
Is there a minimum file size for the parameter “max-size”?

About the system:
Debian 12 with Docker 26
Container: NodRed, InfluxDB1.8, Grafana

Thanks for Support

2

Recreated or restarted? The daemon configuration is just to set the defaults. Check the container metadata (you can do it in portainer too) and see if the log-opts appear there too. If not, you will have to delete the container and recreate it.

3

I think recreated. (Portainer : Container → Container details of the container ->Dublicate/Edi → Deploy the Container)
The Container get a new ID.

Docker run as Service at the Debian Host.
Is it possible that the daemon.json settings have to be loaded into the Docker service (containerd.service , docker.service)?

4

No. But until you check the container metadata I would not start to guess